For tools of the above-mentioned kind, during the machining operation there is supplied, for various reasons, some form of cooling agent to the cutting insert(s) in engagement with the workpiece. The cooling agent may whenever applicable consist of cooling liquid, cooling gas, or a liquid/gas mixture. For instance, in some cases cooling liquid is supplied in order to cool the cutting inserts as well as the workpiece and in other cases air together with misty oil are supplied in order to achieve lubrication and certain cooling. Fundamental for the cooling agent, which may also have lubricating properties, as already mentioned, is the object of giving the machined surfaces of the workpiece optimal characteristics, to cool the cutting inserts and the workpiece, and to obstruct adherence of the machined material to the tool. Another object of the cooling agent is to remove the chips being removed from the workpiece by the tool.
In cutting tools of the kind mentioned, it is known to arrange nozzles, for spraying cooling agent towards cutting inserts included in the tool, in such a way that the cooling liquid is sprayed onto the cutting insert from the side and from above, i.e. obliquely from above. Thus, the nozzles are usually arranged on the coupling part of the tool. In grooving operations and parting operations, when a very narrow cutting edge penetrates deeply into the workpiece, such known cutting tools often achieve an unsatisfactory supply of cooling agent to the cutting insert. In some cases this is due to the workpiece getting in the way of the jet of cooling agent from the nozzle towards the cutting insert. For obviating this problem it has also been tried, in other known cutting tools, to arrange the nozzles on the tool, so that the cooling agent is sprayed onto the cutting insert from above, but also substantially straight from behind. A drawback of this solution is that the cooling agent, before hitting the cutting insert, hits the chips being removed by the cutting insert, so that a major part of the cooling agent jet is deflected and, thus, an unsatisfactory supply of cooling agent to the cutting insert is achieved.